Perovskite quantum material printing process and application thereof

Abstract

The invention relates to the field of perovskite quantum dot materials, and discloses a perovskite quantum material printing process which comprises the following steps: S1, synthesizing perovskite quantum dots through a solution method by using lead iodide and cesium iodide as precursors; s2, performing double coating on the surface of the perovskite quantum dot; s3, carrying out curing treatment on the coated perovskite quantum dot thin film; s4, the coated perovskite quantum dots are dissolved in a solvent; s5, the solution is printed on a substrate in an ink jet printing mode, and a printed film is obtained; and S6, a hot air drying box is used for drying the printing film. According to the perovskite quantum dot, the inner layer is coated with silicon nitride, and the outer layer is coated with silicon dioxide, so that the stability and the environmental influence resistance of the perovskite quantum dot are improved, the surface of the perovskite quantum dot is more effectively protected through the coating structure, the performance of the perovskite quantum dot can be prevented from being eroded by the external environment, and rapid decline of the material in a severe environment is avoided.

Description

Technical Field

[0001] The present invention relates to the technical field of perovskite quantum dot materials, specifically to a printing process and application of perovskite quantum materials. Background Art

[0002] Perovskite quantum dots (PQDs) are a class of nanomaterials with a perovskite structure, usually composed of metal halides or other inorganic compounds, showing unique optoelectronic properties. Perovskite materials have been widely used in various fields due to their excellent optoelectronic properties, especially in solar cells, optoelectronic devices, light-emitting diodes (LEDs), and display technologies. Compared with traditional quantum dot materials, perovskite quantum dots have higher photoelectric conversion efficiency, adjustable spectral range, and lower cost, thus becoming a research hotspot in recent years.

[0003] Perovskite quantum dot materials have unique optical characteristics. For example, they can provide high-brightness luminescence in the visible light range, and their spectral bandwidth can be flexibly controlled by adjusting the size and composition of the quantum dots. In addition, perovskite quantum dots have exceeded many other types of quantum dot materials in terms of photoelectric conversion efficiency and optical stability. Especially in the fields of solar cells and photodiodes, perovskite quantum dot materials show relatively ideal optoelectronic properties. Compared with traditional silicon-based solar cells, perovskite solar cells have higher photoelectric conversion efficiency and lower manufacturing cost, so they have broad application potential in the field of solar cells.

[0004] Although perovskite quantum dot materials have many advantages, they also face some technical challenges in practical applications. Especially in terms of their stability, perovskite quantum dots are often exposed to moisture and oxygen in the air, and are prone to oxidation and hydrolysis, resulting in performance degradation. This phenomenon is particularly serious in high-humidity and high-temperature environments, thus limiting their wide application.

[0005] In addition, the long-term stability and weather resistance of perovskite quantum dots are also a key issue in current research. At room temperature, although perovskite quantum dots can maintain good optoelectronic properties, long-term exposure to environmental conditions such as ultraviolet radiation, high temperature, and humidity will cause degradation of the quantum dots, which poses difficulties for their application in the commercial field. Therefore, how to improve the environmental stability of perovskite quantum dots has become a technical problem that researchers urgently need to solve. Summary of the Invention

[0006] Aiming at the deficiencies of the prior art, the present invention provides a printing process and application of perovskite quantum materials, which solves the problem of performance degradation of existing perovskite quantum dot materials in extreme environments such as high temperature, high humidity, and ultraviolet radiation, and improves their long-term stability and environmental adaptability.

[0007] To achieve the above object, the present invention is realized through the following technical solutions: a perovskite quantum material printing process, including the following steps: S1. Using lead iodide and cesium iodide as precursors, perovskite quantum dots are synthesized by a solution method; S2. Double coating is performed on the surface of the perovskite quantum dots; S3. The coated perovskite quantum dot film is cured; S4. The coated perovskite quantum dots are dissolved in a solvent; S5. The solution is printed onto a substrate by an inkjet printing method to obtain a printed film; S6. The printed film is dried using a hot air drying oven.

[0008] Preferably, the double coating in S2 includes: S21. Inner layer coating, the inner layer coating material is silicon nitride, deposited by chemical vapor deposition; S22. Outer layer coating, the outer layer coating material is silicon dioxide, coated by a solution method and a spin coating method is used to form a coating layer.

[0009] Preferably, the deposition temperature of the silicon nitride in the inner layer coating of S21 is 200°C to 220°C, the deposition time is 20 minutes to 40 minutes, and the thickness of the coating layer is 5nm to 10nm.

[0010] Preferably, the spin coating speed of the silicon dioxide in the outer layer coating of S22 is 1500 rpm to 2500 rpm, the spin coating time is 20 seconds to 40 seconds, and the thickness of the coating layer is 20nm to 30nm.

[0011] Preferably, the molar ratio of the lead iodide to the cesium iodide in the step S1 is 1:1 to 1:2.

[0012] Preferably, in the step S3, the curing treatment is performed by ultraviolet light irradiation, the ultraviolet light intensity is 1.5 mW / cm² to 3 mW / cm², and the irradiation time is 8 minutes to 12 minutes.

[0013] Preferably, in the step S4, the solvent includes dichlorobenzene and ethanol, and the dissolution concentration is 5 mg / mL to 15 mg / mL.

[0014] Preferably, in the step S5, the nozzle diameter used for the inkjet printing is 20μm to 40μm, the printing speed is 0.1 m / s to 0.3 m / s, the number of printing layers is 3 layers to 5 layers, and the thickness of each layer is controlled at 30nm to 50nm.

[0015] Preferably, in the step S6, the parameter setting temperature of the hot air drying oven is 60°C to 80°C, and the drying time is 20 minutes to 40 minutes.

[0016] An application of a perovskite quantum material printing process, which is used in the production of displays, solar cells, and LED lighting devices.

[0017] The present invention provides a perovskite quantum material printing process and its application. It has the following beneficial effects: 1. The present invention adopts a double coating technology, with silicon nitride coated on the inner layer and silicon dioxide coated on the outer layer, significantly improving the stability of perovskite quantum dots and their resistance to environmental influences. Through this coating structure, the surface of perovskite quantum dots is more effectively protected, enabling them to resist the erosion of external environments (such as moisture and oxygen) on their performance and avoiding the rapid decline of the material in harsh environments.

[0018] 2. The present invention further enhances the optoelectronic stability and ultraviolet resistance of quantum dots by precisely controlling the thickness and deposition conditions of the coating layer. The combination of silicon nitride on the inner layer and silicon dioxide on the outer layer enables perovskite quantum dots to not only have excellent light absorption characteristics but also maintain stable optoelectronic properties under ultraviolet irradiation, avoiding the problem of photo-degradation caused by ultraviolet radiation.

[0019] 3. The present invention combines refined printing parameters to ensure the uniformity and high quality of the thin film. This precise control method enables the printed layer of quantum dots to be evenly distributed, avoiding the phenomena of uneven or unstable coatings commonly seen in traditional processes, not only improving production efficiency but also significantly reducing material waste. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic process flow diagram of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0021] The following will clearly and completely describe the technical solutions of the present invention in conjunction with the drawings of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of them. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0022] Please refer to the attached Figure 1 , the embodiment of the present invention provides a perovskite quantum material printing process, including the following steps: S1. Using lead iodide and cesium iodide as precursors, perovskite quantum dots are synthesized by a solution method, and the molar ratio of lead iodide to cesium iodide is 1:1 to 1:2; First, step S1 mainly involves the synthesis process of perovskite quantum dots. By using lead iodide and cesium iodide as precursors and combining with the solution method, perovskite quantum dots are synthesized. In the present invention, the key to this synthesis process lies in the precise control of the proportion of precursors, reaction temperature, and reaction time to ensure that perovskite quantum dots with excellent optoelectronic properties and stability are finally obtained. Specifically, the core objective of this step is to obtain perovskite quantum dots with uniform size and strong optoelectronic stability, so as to exhibit excellent properties in subsequent coating, printing, and applications.

[0023] In this embodiment, first, the synthesis of perovskite quantum dots is carried out by the solution method. Specifically, lead iodide and cesium iodide are used as precursors, and the molar ratio range of lead iodide to cesium iodide is 1:1 to 1:2. The selection of this ratio plays a decisive role in the luminescence characteristics and stability of the quantum dots. As an option, the proportion of lead iodide can be slightly higher than that of cesium iodide to increase the optoelectronic conversion efficiency of the quantum dots.

[0024] In the specific synthesis process, the solvent dimethylsulfinamide is used as the solvent, the reaction temperature is set between 100 °C and 120 °C, and the reaction time is 1 hour to 2 hours. By controlling the reaction temperature and time, the size and morphology of perovskite quantum dots can be effectively adjusted. Generally, a higher temperature helps to accelerate the reaction of precursors, but too high a temperature will lead to too large a particle size of the quantum dots. Therefore, a balance needs to be achieved between temperature and time. Specifically, by reacting within the range of 100 °C to 110 °C for 1.5 hours, quantum dots with a particle size of 6 nm to 8 nm can be obtained.

[0025] After the reaction is completed, a pure perovskite quantum dot solution is obtained by centrifugal separation to remove unreacted precursors and solvents. As an option, the rotation speed of centrifugal separation can be set to 5000 rpm to 8000 rpm to ensure the collection of quantum dots and the cleanliness of the solution.

[0026] The technical solution of the present invention has successfully achieved the synthesis of high-quality perovskite quantum dots by precisely controlling the reaction conditions. This synthesis method has significant advantages in improving optoelectronic properties, stability, and quantum efficiency, laying a solid foundation for subsequent coating and applications.

[0027] S2. Perform double coating on the surface of perovskite quantum dots; including: S21. Inner layer coating, the inner layer coating material is silicon nitride, deposited by chemical vapor deposition. S22. Outer layer coating, the outer layer coating material is silicon dioxide, coated by the solution method and using the spin coating method to form a coating layer.

[0028] In this embodiment, the material used for the inner layer coating is silicon nitride, which is deposited by chemical vapor deposition. As the inner layer coating material, silicon nitride has good chemical stability and oxidation resistance, and can effectively isolate the quantum dots from the invasion of moisture and oxygen, preventing oxidation reactions on the surface of the quantum dots.

[0029] Specifically, the deposition temperature of the inner layer silicon nitride is controlled between 200 °C and 220 °C, and the deposition time is between 20 minutes and 40 minutes. During this process, the thickness of the silicon nitride coating layer can be precisely controlled between 5 nm and 10 nm to ensure the coating effect and stability. In some embodiments, the selection of deposition time and temperature can be adjusted according to the changes in reaction conditions to optimize the quality and consistency of the coating layer.

[0030] As an option, when performing silicon nitride coating, high-purity nitrogen and silane gases can be used as reaction sources to ensure the uniformity and high quality of the silicon nitride layer. In addition, the thickness and quality of the silicon nitride layer can be precisely controlled by adjusting parameters such as gas flow rate and pressure during the deposition process, thereby improving the stability of perovskite quantum dots.

[0031] S22. Outer layer coating: The material used for the outer layer coating is silica, which is coated by solution method and a coating layer is formed by spin coating. Silica has strong ultraviolet resistance and chemical stability, and can effectively enhance the stability of quantum dots under ultraviolet irradiation and high-temperature environments.

[0032] Specifically, the outer layer silica coating is carried out by solution coating. By uniformly coating the silica solution on the surface of the quantum dots, and then spin coating is used for uniform coating. The rotation speed range during spin coating is 1500 rpm to 2500 rpm, and the spin coating time is 20 seconds to 40 seconds to ensure the uniformity and stability of the coating layer. The thickness of the silica coating layer is controlled between 20 nm and 30 nm, and can be flexibly adjusted according to actual needs.

[0033] In some embodiments, the solution concentration during the outer layer coating process can be optimized according to the state of the quantum dot surface and quality requirements. The concentration of the solution is generally 5% to 15%, and heat treatment is required after coating to further enhance the adhesion and stability of the coating layer. The heat treatment temperature can be set at 100 °C to 120 °C, and the heat treatment time is 10 minutes to 30 minutes.

[0034] As an option, when performing the outer layer coating, a silanization reagent can be used to modify the silica, thereby improving its adhesion to the quantum dots and enhancing the stability and weather resistance of the coating layer.

[0035] Through the above double - coating technology, the combination of the inner and outer layer materials effectively improves the optoelectronic stability and environmental resistance of perovskite quantum dots. Especially in ultraviolet, high - humidity, and high - temperature environments, the performance of the quantum dots is significantly protected and enhanced. This technology not only solves the problem of insufficient ultraviolet protection and environmental adaptability in traditional coating methods but also provides longer - term stability and stronger environmental resistance for quantum dots in application fields such as displays, solar cells, and LED lighting.

[0036] S3. Cure the coated perovskite quantum dot film. First, after the coating of the perovskite quantum dot film is completed, wait for the film to dry naturally and the solvent to evaporate completely, and then the curing process can be carried out. The curing methods include ultraviolet curing and thermal curing. Which curing method to use specifically depends on the material characteristics and application requirements.

[0037] In a possible implementation, ultraviolet light irradiation is used for curing. The intensity of the ultraviolet light is set between 1.5 mW / cm² and 3 mW / cm², and the irradiation time is controlled between 8 minutes and 12 minutes. The ultraviolet curing process can quickly and efficiently complete the cross - linking reaction of the coating layer, making the coating layer adhere more firmly to the surface of the perovskite quantum dots, thereby improving their stability. The wavelength of the ultraviolet light should be selected between 200 nm and 400 nm to ensure that it can effectively penetrate the coating layer and cross - link the interior of the material.

[0038] As an option, the intensity and irradiation time of ultraviolet light irradiation can be adjusted according to the thickness and quality requirements of the coating layer. For example, in some embodiments, higher - intensity ultraviolet light (close to 3 mW / cm²) and shorter irradiation time (8 minutes) are used to improve the curing efficiency and speed, which is suitable for production processes that require rapid curing. Conversely, lower ultraviolet light intensity and longer irradiation time are suitable for thicker coating layers.

[0039] In another implementation, thermal curing can be used. The specific curing temperature is set between 90°C and 110°C, and the curing time is 20 minutes to 40 minutes. Thermal curing is suitable for materials that are not suitable for ultraviolet curing or in cases where curing is required under high - temperature conditions. This process enhances the adhesion and weather resistance of the coating layer by heating the coating layer to cause cross - linking reactions of its internal molecules. The thermal curing process can be completed in an atmosphere furnace or a hot - air drying oven to ensure uniform temperature distribution and avoid uneven coating layers or cracking caused by excessive temperature differences.

[0040] Specifically, the temperature and time settings for thermal curing need to be adjusted according to the thickness of the thin film, the characteristics of the coating material, and the requirements of the final application. For thinner coatings, lower temperatures (such as 90 °C) and shorter curing times (such as 20 minutes) can achieve the required curing effect; while for thicker coatings, slightly higher temperatures and longer curing times are required to ensure complete curing.

[0041] S4. Dissolve the coated perovskite quantum dots in a solvent; First, after the perovskite quantum dot thin film is fully dried and the solvent is completely volatilized after coating, the coated quantum dots are dissolved. To ensure the uniform dispersion of perovskite quantum dots in the solution, an appropriate solvent needs to be selected. In some embodiments, solvents such as dichlorobenzene, ethanol, or dimethyl sulfoxide can be used. These solvents can effectively dissolve perovskite quantum dots and ensure their uniform dispersion.

[0042] Dichlorobenzene is commonly used for quantum dot dissolution because it has a moderate polarity, can dissolve most perovskite quantum dots, and has good volatility, which is suitable for subsequent printing processes. Selecting the appropriate solvent is crucial for the solubility and dispersibility of quantum dots. If the solvent polarity is too strong or too weak, it may lead to incomplete dissolution of quantum dots or precipitation, thus affecting the subsequent printing effect.

[0043] During the dissolution process, the concentration of the solvent also needs to be controlled within an appropriate range to ensure the uniform dispersion of quantum dots and the stability of the solution. Generally, the dissolution concentration is 5 mg / mL to 15 mg / mL. The specific concentration selection depends on the particle size of the quantum dots, the thickness of the coating layer, and the characteristics of the solvent used. A lower concentration may result in insufficient quantum dot concentration in the solution, while too high a concentration may lead to too high a solution viscosity, affecting the quality of inkjet printing.

[0044] As an option, during the dissolution process, ultrasonic treatment can be used to help the quantum dots disperse uniformly in the solvent. Ultrasonic treatment can effectively break the aggregates between quantum dots, promote their dispersion in the solution, and avoid the formation of uneven particle agglomerates. Generally, the ultrasonic treatment time is 10 minutes to 30 minutes, and the ultrasonic power can be set to 100 W to 300 W to ensure the full dispersion of quantum dots in the solvent.

[0045] In some embodiments, after dissolution and ultrasonic treatment, in order to further ensure the stability of the solution, a certain centrifugation treatment can be carried out to remove large particle impurities and incompletely dissolved solid substances in the solution. The centrifugation rate is usually set to 3000 rpm to 5000 rpm, and the treatment time is 10 minutes to 15 minutes to ensure the purity and stability of the solution.

[0046] S5. Print the solution onto the substrate by inkjet printing to obtain a printed film; First, an inkjet printing device is used. This device precisely sprays the perovskite quantum dot solution onto the selected substrate through a nozzle. The choice of inkjet printing depends on its characteristics of high precision and high efficiency, and is suitable for applications with high requirements for film thickness, uniformity, and pattern accuracy. In some embodiments, the inkjet printer used can achieve high-resolution printing and is applicable to different types of substrate materials, such as glass, plastic, or metal, etc.

[0047] As an option, during the inkjet printing process, the nozzle diameter can be controlled between 20μm and 40μm to ensure that the ejected ink droplets are uniform and tiny, guaranteeing the smoothness and uniformity of the printed film. The choice of nozzle is crucial for the film quality. A smaller nozzle diameter enables more precise ink droplet control, thereby improving the printing effect. The printing speed is usually set between 0.1m / s and 0.3m / s. This speed can balance the printing efficiency and film quality, avoiding uneven ink droplet distribution caused by too fast or too slow speed.

[0048] In some embodiments, the number of printed layers can be set to 3 to 5 layers, and the thickness of each layer is controlled between 30nm and 50nm. Through multi-layer printing, the thickness of the quantum dot film can be better controlled, while ensuring the uniformity and stability of the film. The multi-layer printing method can not only improve the overall performance of the film but also reduce the defects that may occur during single-layer printing.

[0049] During the printing process, to ensure the stability and effect of inkjet printing, parameters such as the driving voltage of the nozzle, printing pressure, and the viscosity of the solution can be adjusted. As an option, the viscosity of the quantum dot solution should be maintained between 20cP and 50cP. This viscosity range helps with precise ink droplet control, preventing the solution from being too thin or too viscous, which may cause uneven dripping or clogging during the inkjet process.

[0050] In certain embodiments, hot air heating can also be used as an auxiliary drying method during the inkjet printing process. By blowing gentle hot air onto the substrate surface during inkjet printing, the volatilization of the solvent can be accelerated, enabling each layer of the film to solidify quickly, preventing cross-contamination of the solvent between layers, and ensuring the stability of the film quality.

[0051] In addition, to avoid excessive evaporation and affect the performance of the quantum dots, too high a temperature should be avoided during the printing process. Control the ambient temperature at 20°C to 30°C and the relative humidity at 40% to 60% during the printing process to prevent uneven deposition of quantum dots or film wrinkling caused by excessive solvent volatilization during inkjet printing.

[0052] S6. Dry the printed film using a hot air drying oven.

[0053] First, place the printed perovskite quantum dot film in a hot air drying oven for drying. The hot air drying oven heats the air and blows hot air to help the solvent evaporate quickly, thus achieving the drying of the film. The selection of the drying temperature is very important. Generally, it is set between 60°C and 80°C. This temperature range can not only ensure the full volatilization of the solvent but also avoid damage to the quantum dot film or degradation of the coating material caused by too high temperature.

[0054] In some embodiments, the drying temperature can be slightly adjusted according to actual needs. In the case of a lower temperature (such as 60°C), the drying process is relatively slow, but the solvent can be removed more gently, reducing any potential impact on the quantum dot film; while in the case of a higher temperature (such as 80°C), the drying speed is faster, but special attention needs to be paid to avoid cracks or unevenness of the film caused by too rapid solvent volatilization.

[0055] The drying time is set to 20 minutes to 40 minutes in some embodiments. This period of time is sufficient to ensure the complete volatilization of the solvent in the film without causing changes in the material properties. The specific selection of the drying time should be flexibly adjusted according to the thickness of the film, the solution concentration, and the drying temperature. Thicker films may require a longer drying time to ensure the complete volatilization of the solvent in each layer.

[0056] As an option, the air flow rate of the drying oven also has an important impact on the drying effect. The air flow rate is generally set to 1 m / s to 2 m / s to ensure that the air flow evenly covers every part of the film surface, accelerating the solvent volatilization process and avoiding uneven drying caused by uneven air flow. Uniform air flow helps to keep the film surface smooth and flat, avoiding problems such as bubbles or solvent residues.

[0057] In some embodiments, humidity control is also one of the important factors to ensure the drying effect. To avoid moisture in the air interfering with the drying process, the environmental humidity of the drying oven is usually maintained between 40% and 60%. This humidity range can effectively prevent moisture from entering the film surface and affecting the uniformity and stability of the film.

[0058] Optimization of the drying process: To further optimize the drying effect, a stepwise temperature increase method can be used during the drying process, that is, starting from a lower temperature (such as 60°C) and gradually increasing to the target temperature (such as 80°C). This stepwise temperature increase method can reduce the thermal stress caused by too rapid temperature change of the film and further improve the quality and stability of the film.

[0059] In some embodiments, a multi-layer drying method can be adopted, that is, the film is dried separately in multiple drying cycles, and the temperature and time of each cycle can be precisely controlled according to the characteristics of the film. In this way, it can be ensured that the film is more uniform during the drying process and further reduce film defects caused by uneven drying.

[0060] Example 1: Application of perovskite quantum materials printing process in displays; Background and objective: This example involves the application of perovskite quantum materials in displays. In particular, to improve the color saturation and brightness of the display screen, perovskite quantum dots are used as the light-emitting layer. Displays are required to have high color gamut coverage and brightness to improve the visual effect, especially for high-end TVs and display devices.

[0061] Steps and conditions: S1. Synthesis of perovskite quantum dots: Precursor ratio: Lead iodide and cesium iodide are used as precursors, and the molar ratio is 1:1. To improve the optoelectronic properties of the quantum dots, the selected lead iodide and cesium iodide are fully dissolved in the solvent.

[0062] Synthesis conditions: The reaction temperature is set at 100 °C to 110 °C, the reaction time is 1.5 hours, and the solvent dimethyl sulfinamide is used. After the reaction, centrifugation is carried out to obtain a pure perovskite quantum dot solution with the particle size controlled between 6 nm and 8 nm to ensure good optoelectronic properties.

[0063] S2. Double coating: Inner coating: Silicon nitride is selected as the inner coating material and deposited by chemical vapor deposition. The deposition temperature is controlled at 210 °C to 220 °C, the deposition time is set at 25 minutes, and the coating layer thickness is controlled at 8 nm, effectively improving the optoelectronic stability of the quantum dots and reducing surface defects.

[0064] Outer coating: Silicon dioxide is used as the outer coating material and coated by spin coating. The spin coating speed is 2000 rpm, the spin coating time is 30 seconds, and the coating layer thickness is set at 25 nm. The outer coating ensures that the quantum dots are not eroded by environmental humidity and oxygen during the use of the display, improving their stability.

[0065] S3. Curing treatment: The curing treatment is carried out by ultraviolet light irradiation. The ultraviolet light intensity is 2 mW / cm², and the irradiation time is set at 10 minutes. The curing effect is significant, ensuring good bonding between the coating layer and the perovskite quantum dots. To ensure that the ultraviolet light curing process does not affect the luminescence characteristics of the quantum dots, the ultraviolet light irradiation intensity and time need to be precisely controlled.

[0066] S4. Solution preparation and printing: The coated perovskite quantum dots are dissolved in dichlorobenzene solvent at a dissolution concentration of 10 mg / mL, and ultrasonic treatment is used to ensure uniform dispersion of the solution and prevent precipitation of the quantum dots. The ultrasonic treatment time is 30 minutes to ensure the uniformity and stability of the quantum dots.

[0067] Thin film printing is carried out using inkjet printing technology. The nozzle diameter is 30 μm, the printing speed is controlled at 0.2 m / s, the number of printed layers is 4 layers, and the thickness of each layer is controlled at 40 nm. The thickness of each layer needs to be strictly controlled to avoid the influence of the over-thick quantum dot thin film on the optoelectronic performance.

[0068] S5. Drying: During the drying process, a hot air drying oven is used for solvent evaporation. The temperature is set at 70 °C and the drying time is 30 minutes to ensure that all solvents in the quantum dot thin film are completely evaporated, avoiding the influence of solvent residues on the film stability. The wind speed of the drying equipment is controlled at 1.5 m / s to ensure uniform drying.

[0069] S6. Assembling the display: The perovskite quantum dot thin film is used as the light-emitting layer and applied to the light-emitting panel of the OLED display. In combination with other electronic components such as conductive films and transparent electrodes, a complete display is finally assembled. The quantum dot thin film plays a role in enhancing brightness and improving color gamut coverage in the display.

[0070] Results and advantages: The display processed by this process has a significant improvement in the color gamut performance of red and blue, with the color saturation increased by about 30%, and the display effect is more vivid and natural.

[0071] In terms of brightness, the brightness of the display has increased by 20%. Especially in high-light environments, the color stability and contrast have been significantly improved.

[0072] Example 2: Application of perovskite quantum material printing process in solar cells; Background and objective: This example involves the use of perovskite quantum dots in solar cells to improve the photoelectric conversion efficiency, especially the application in enhancing the infrared light absorption and overall efficiency of solar cells. Perovskite quantum dots can effectively expand the light absorption range of solar cells, especially the absorption of long-wavelength light.

[0073] Steps and conditions: S1. Synthesis of perovskite quantum dots: Precursor ratio: Lead iodide and cesium iodide are used, and the molar ratio is 1:1.5. To improve the infrared absorption performance, a slightly higher molar ratio of cesium iodide is selected.

[0074] Synthesis Temperature and Time: The reaction temperature was set at 110 °C, and the reaction time was 2 hours. Dimethyl sulfoxide was used as the solvent to ensure complete reaction, and the particle size of the obtained perovskite quantum dots was controlled between 6 nm and 8 nm.

[0075] S2. Double Coating: Inner Coating: Silicon nitride was used for the inner coating, deposited by chemical vapor deposition at a deposition temperature of 215 °C and a deposition time of 30 minutes. The thickness of the coating layer was controlled at 7 nm. The inner coating can reduce the defects on the surface of the quantum dots and improve their stability.

[0076] Outer Coating: Silica was used for the outer coating, coated by spin coating at a spin coating speed of 2200 rpm and a spin coating time of 25 seconds. The thickness of the coating layer was 20 nm to enhance the protection of the quantum dots by the external environment.

[0077] S3. Curing Treatment: Thermal curing was used for the curing treatment, with the temperature set at 100 °C and the curing time at 20 minutes to ensure the stability and adhesion of the coating layer.

[0078] S4. Preparation of Perovskite Quantum Dot Solution: The coated quantum dots were dissolved in dichlorobenzene at a dissolution concentration of 12 mg / mL, and ultrasonic treatment was used to ensure uniform dispersion of the solution.

[0079] S5. Inkjet Printing: Inkjet printing was used, with a nozzle diameter of 30 μm, a printing speed of 0.25 m / s, and 4 printing layers. The thickness of each layer was controlled at 35 nm. Through multi-layer printing, a relatively uniform quantum dot thin film can be obtained.

[0080] S6. Drying: Hot air drying oven was used for drying, with the temperature set at 75 °C and the drying time at 25 minutes to ensure complete volatilization of the solvent in the thin film.

[0081] S7. Assembly of Solar Cells: The perovskite quantum dot thin film was used as the light absorption layer and integrated into the light absorption layer of the solar cell, combined with other optoelectronic conversion layers to optimize the photoelectric conversion efficiency of the cell.

[0082] Results and Advantages: Through this process, the photoelectric conversion efficiency of the solar cell under low light conditions was increased by 15%, especially the absorption in the infrared spectral region was enhanced.

[0083] The overall photoelectric conversion efficiency was improved, and under long-term working conditions, the stability and efficiency decay of the battery were small.

[0084] Example 3: Application of Perovskite Quantum Material Printing Process in LED Lighting Devices; Background and Objectives: In this example, perovskite quantum dots are applied to LED lighting devices to improve the brightness, luminous efficiency, and color quality of LEDs, especially in enhancing the green and blue light emission performance.

[0085] Steps and Conditions: S1. Synthesis of Perovskite Quantum Dots: Precursor Ratio: The ratio of lead iodide to cesium iodide is 1:2. To optimize the emission performance of blue and green light, an appropriate precursor ratio is selected.

[0086] Synthesis Temperature and Time: The reaction temperature is 100 °C, the reaction time is 1 hour, the solvent is dimethyl sulfoxide, and the quantum dot particle size is controlled at 6 nm to ensure its optoelectronic efficiency.

[0087] S2. Double Coating: Inner Coating: Silicon nitride is used for the inner coating, CVD deposition, the deposition temperature is 205 °C, the deposition time is 25 minutes, and the coating layer thickness is 6 nm.

[0088] Outer Coating: Silicon dioxide is used for the outer coating, the spin coating speed is 2200 rpm, the spin coating time is 30 seconds, and the coating layer thickness is 25 nm.

[0089] S3. Curing Treatment: Curing is carried out by ultraviolet light irradiation, the ultraviolet light intensity is 2 mW / cm², and the irradiation time is 10 minutes to ensure good bonding between the coating layer and the quantum dots.

[0090] S4. Dissolution and Printing: The coated quantum dots are dissolved in dichlorobenzene, the dissolution concentration is 10 mg / mL, and ultrasonic treatment is used to ensure uniform dispersion.

[0091] Inkjet printing is used, the nozzle diameter is 30 μm, the printing speed is 0.25 m / s, the number of printed layers is 4 layers, and the thickness of each layer is 40 nm.

[0092] S5. Drying: Drying is carried out using a hot air drying oven, the temperature is set at 70 °C, and the drying time is 30 minutes to ensure complete volatilization of the solvent in the film.

[0093] S6. Assembly of LED Devices: The perovskite quantum dot film is applied to the light-emitting layer of the LED and combined with traditional semiconductor materials to assemble a high-efficiency LED lighting device.

[0094] Results and Advantages: LED lighting devices using perovskite quantum dots have more vivid colors, especially with a significant improvement in the emission of green and blue light, and the energy efficiency is increased by more than 10%.

[0095] Although the embodiments of the present invention have been shown and described, it will be understood by those of ordinary skill in the art that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the present invention, and the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. Perovskite quantum material printing process, characterized in that: The following steps are involved: S1, using lead iodide and cesium iodide as precursors, synthesizing perovskite quantum dots by solution method; S2, double coating the surface of the perovskite quantum dots; S3, curing the coated perovskite quantum dot film; S4, dissolving the coated perovskite quantum dots in a solvent; S5, printing the solution onto a substrate by inkjet printing to obtain a printed film; S6. Use a hot air drying oven to dry the printed film.

2. The perovskite quantum material printing process according to claim 1, characterized in that: The S2 double wrap includes: S21, inner layer coating, wherein the inner layer coating material is silicon nitride, which is deposited by chemical vapor deposition; S22, outer layer coating, the outer layer coating material is silicon dioxide, and the coating layer is formed by solution coating and spin coating.

3. The perovskite quantum material printing process according to claim 1, characterized in that: The deposition temperature of the S21 inner layer coated with silicon nitride is 200° C. to 220° C., the deposition time is 20 minutes to 40 minutes, and the coating layer thickness is 5 nm to 10 nm.

4. The perovskite quantum material printing process according to claim 1, characterized in that: The spin coating speed of the S22 outer layer coated with silicon dioxide is 1500 rpm to 2500 rpm, the spin coating time is 20 seconds to 40 seconds, and the coating layer thickness is 20 nm to 30 nm.

5. The perovskite quantum material printing process according to claim 1, characterized in that: The molar ratio of the lead iodide to the cesium iodide in step S1 is 1:1 to 1:

2.

6. The perovskite quantum material printing process according to claim 1, characterized in that: In the S3 step, the curing treatment is performed by ultraviolet light irradiation, the ultraviolet light intensity is 1.5mW / cm² to 3mW / cm², and the irradiation time is 8 minutes to 12 minutes.

7. The perovskite quantum material printing process according to claim 1, characterized in that: The solvent in step S4 includes dichlorobenzene and ethanol, wherein the dissolving concentration is 5 mg / mL to 15 mg / mL.

8. The perovskite quantum material printing process according to claim 1, characterized in that: The nozzle diameter used for the inkjet printing in step S5 is 20 μm to 40 μm, the printing speed is 0.1 m / s to 0.3 m / s, the number of printing layers is 3 to 5 layers, and the thickness of each layer is controlled at 30 nm to 50 nm.

9. The perovskite quantum material printing process according to claim 1, characterized in that: In step S6, the temperature of the hot air drying oven is set to 60° C. to 80° C., and the drying time is set to 20 minutes to 40 minutes.

10. An application of a perovskite quantum material printing process, according to the perovskite quantum material printing process according to any one of claims 1 to 9, characterized in that: This process is used in the production of displays, solar cells, and LED lighting devices.

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